1. Field of the Invention
Certain geothermal brines contain high non-condensible gas concentrations. Typically, these brines are flashed in a pre-flash vessel to remove the non-condensible gases from the rest of the brine. By pre-flashing the geothermal brine, however, a considerable fraction of the geothermal steam is also flashed off. This steam is typically recovered in a shell and tube reboiler.
2. Description of the Prior Art
Because of the nature of the pre-flash vapor, heat transfer performance of the shell and tube reboiler is poor. As a result, expensive tube alloys, such as Inconel 625, are required because of the corrosive nature of the pre-flash vapor. In addition, because of the temperature driving force required for steam generation in a shell-and-tube heat exchanger, the energy recovery is limited, particularly for high concentrations of non-condensible gases.
Because of these and other drawbacks in the handling of geothermal brines containing non-condensible gases, a need exists for improvements in the recovery of energy from such brines to obtain maximum efficiency while substantially eliminating corrosion problems.
Prior patents relating to the processing of geothermal brines include U.S. Pat. Nos. 3,953,972 and 4,138,851.